<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		*{
			margin: 0;
			padding: 0;
		}
		/*background: radial-gradient(center, shape size, start-color, ..., last-color);*/
		/*radial-gradient径向渐变指从一个中心点开始沿着四周产生渐变效果*/
		.box {
			position: relative;
			width: 400px;
			height: 400px;
			/*background: radial-gradient(50% 50% , red , green , yellow);*/
			/*不兼容?*/
			/*background: radial-gradient(10% 20%,yellow,red,green);*/
	      	background: -webkit-radial-gradient(10% 20%,yellow,red,green);

			border-radius: 50%;
		}
		.box::after{
			display: block;
			content: '';
			position: absolute;
			left: 50%;
			bottom: -70px;
			width: 600px;
			height: 100px;
			border-radius: 50%;
			background-color: gray;
		}
	</style>
</head>
<body>
	<div class="box">
		
	</div>
</body>
</html>